Windings used in modern electrical machine applications are commonly configured in any of various forms including, for example, standard-wind configurations, S-wind configurations or segmented conductor configurations. S-wind configurations typically include a continuous length of wire that is wound in an out of various slots in the core portion of the electric machine to form a complete winding. The wire includes relatively straight lengths that are positioned within the slots of the core portion and curved lengths that extend between in-slot portions at the ends of the core portion. Similarly, in a segmented winding configuration, the windings typically comprise a plurality of segmented conductors which include in-slot portions and ends that are connected together. The in-slot portions of the conductors are positioned in the slots of a laminated core portion of the electric machine (e.g. stator slots), and the ends of the conductors are connected to form windings for the electric machine.
Segmented conductors for electric machines are often provided in the form of U-shaped conductors which include two legs and a central U-turn or bend portion extending between the legs. Such segmented conductors are typically created by bending and twisting wire bars into U-shaped conductors with two legs and a U-turn between the legs. The two legs are separated by a given span which allows the conductor to extend across a number of stator slots by virtue of the U-turn alone. The legs of the conductors are then inserted into the slots of the core from an insertion end of the core. After insertion of the conductors into the slots of the core, the bend portions are positioned on one side of the core and the leg ends extend from the other side of the core. The legs ends may then be bent to appropriate positions, often with a first leg typically bent in one direction and another leg bent in the opposite direction such that the entire segmented extends a given slot span (e.g., 12 slots). Finally, the tips of the leg ends are connected together at the connection side of the stator to complete the windings. These connections include adjacent leg ends that are aligned directly and welded together, non-adjacent leg ends that are connected through jumper wires, and terminal connections. Together, the connected conductors form the complete winding arrangement.
Although the conductors are connected together at their ends, care must be taken to ensure that adjacent conductors do not touch each other and short-circuit the designed winding arrangement. Accordingly, electrical insulation is typically provided on the conductors to electrically insulate the conductors from one another. Segmented conductor insulation systems typically include an enamel coating that is applied and bonded directly on the bare copper wire by the wire manufacturer. Different grades of materials and temperature classes may be used for this initial layer of insulation. The electric machine manufacturer also typically includes a slot liner or insulation sleeve positioned along the walls of the slots in the lamination stack. The insulation sleeve prevents the conductors from short-circuiting against the core.
In addition to an enamel coating on the conductors and insulation sleeves in the core slots, some winding arrangements also include insulation wedges. The insulation wedges are positioned across the radial openings to the core slots to further insulate the conductors from short-circuiting against the core and to maintain the position of the conductors in the slots during assembly of the electric machine. Insulation wedges may be utilized with different winding configurations, including standard wind configurations, S-wind configurations, and segmented conductor configurations. However, the application of such insulation wedges in electric machines can be problematic due to the design of the core, the conductors, or the windings in some of these machines. In some instances, for example, the size or geometry of the core, the conductors, or both makes installation and alignment of the insulation wedges in the core slots difficult.
Accordingly, it would be advantageous to provide an insulation component for electric machines which provides high integrity insulation and facilitates assembly while also avoiding the wedge paper installation problem that results from some core designs. It would be advantageous if such insulation component could be provided easily and at relatively low cost to the manufacturer. It would also be advantageous if such insulation component could be used in association with different winding configurations.